The present invention relates to a method of manufacturing an optical wave guide device, and more particularly to a method of connecting an optical fiber array to an optical wave guide chip.
As the optical wave guide device, there have been known a 1.times.N branch device that branches a light in one optical fiber into lights for N optical fibers, an M.times.M switch device that distributes any light in M optical fibers to any one of M optical fibers, and so on.
Those optical wave guide devices are so designed as to connect the optical fibers to both ends of the optical wave guide chip section that performs the above function, and because several optical fibers are connected to both ends of the chip, an optical fiber array that has the optical fibers arrayed is used.
Up to now, as shown in FIG. 4, the connection of an optical wave guide chip (5) to optical fiber arrays (1, 3) is accomplished through a method in which a light is inputted from an optical fiber (7) on one end side of the optical wave guide chip (5), respective light receiving units (13) are connected to corresponding optical fibers (7) on an opposite end side of the optical wave guide chip (5), and the optical wave guide chip (5) and the optical fiber arrays (1, 3) are positioned so that the amount of received light of those light receiving units (13) becomes maximum before the respective units are fixed.
Pitches between the respective optical fibers are set to a predetermined value by use of the optical fiber array, and pitches between input/output ports of the branched waveguide on the optical wave guide chip are also set to a predetermined value. However, because of manufacturing fluctuations, the respective pitches and pitches between the optical fiber arrays and the optical wave guide chip 5 are not always identical. Therefore, even if one optical fiber on the optical fiber array can be connected to one of the branched waveguides so that the amount of transmitted light becomes maximum, the amount of transmitted light of the optical fiber which is connected to another branched waveguide cannot be always set to the same value. Accordingly, taking the manufacturing fluctuations into account, the optical fiber arrays and the optical wave guide chip need to be connected at a position where a whole sum of the amount of transmitted light of each of the plural optical fibers is maximum. Simultaneously, the amount of light is measured on the respective end surfaces of the plural optical fibers by the light receiving units, and while the amount of light from the respective optical fibers is compared with each other, or a total amount of the light is obtained, a relative position between the optical fiber arrays and the optical wave guide chip needs to be determined.
The present invention has been made in view of the above problem inherent in the prior art, and therefore an object of the present invention is to provide a method through which it is capable of adjusting an optical axis by a single light receiving unit without using a plurality of expensive light receiving units, and is also capable of adjusting the optical axis with ease in a short period of time.